Pharynx

Question 1

What are the pharyngeal muscles and innervations?

Answer 1

1. Outer circular constrictors

superficial, middle and inferior constrictors

All innervated by the pharyngeal branch of the vagus nerve

2. inner longitudinal constrictors
   - palatopharyngeous, salpingopharyngeous
   - stylopharyngeus * glossopharyngeal
   - all function to elevate the pharynx during swallowing.

Question 2

What are the extrinsic muscles of the palate?

Answer 2

1. Tensor palati - flattens and lifts the palate
   - V3
2. Levator palati - lifts the palate
   - vagus nerve
   - and opens the auditory tube
3. all other muscles of the palate (uvula)
   - vagus

Question 3

Describe the sequence of deglutination

Answer 3

1. Chew up the food (V3)
2. keep food between molars using cheek (buccinator - facial) and sensing the food (buccal nerve- V3)
3. Secrete saliva - parotid (IX) and sublingual,mandibular facial nerve (VII)
4. Taste the food with tongue (facial nerve + glossopharyngeal)
5. Tongue moves bolus of food back (hypoglossal)

Phase two (involuntary)

6. Mucosa of pharynx senses contact of food (gag reflex) (IX)
7. Seal off the nasopharynx by levator and tensor palatis (X and V3)
8. Pharynx is elevated by longitudinal constrictors. (X, IX), and suprahyoids (VII, V3)
9. Contractions circular - vagus (X)

Question 4

Describe the muscles and innervations of the larynx

Answer 4

Muscles:
1. Posterior cricoarytenoid muscle - abduct vocal folds

2. Lateral cricoarytenoid - adducts the folds
3. Cricothyroid muscle - tenses vocal folds

Innervation: (Superior laryngeal branches into internal and external

1. general sensation above the vocal folds > INTERNAL laryngeal
2. general sensation below the vocal folds > recurrent/INFERIOR laryngeal nerves
   Motor: of posterior and lateral cricoarytenoids
3. motor to cricothyroid: External laryngeal nerve.
4. Vocalis muscle - shortens and relaxes the vocal folds > inferior laryngeal nerve